Manufacture of glycoheptonic acid.



UNITED STATES PATENT oFFIoE.

ARTHUR LIEBREGHT, 0F FRANKEORT-QN-THE- MAIN, AND GEORG ROSENFELD, 0F

BRESLAU, GEBMANY.

'MANUFACTURE OF GLYCOHEPTONIC ACID,

No Drawing.

Specification of Letters Patent.

} Application filed April 20, 1912. Serial No. 692,121.

Patented Apr. 11, i or a.

To all whom it may concern Be it known that we, ARTHUR LIEBRECHT, D., chemist, and Gamma RosnNrnLu, Ph. 1)., professor of medicine, citizensof the Empire of'Germany, residing, respectively, at Fraukfort-on-the-Main and Breslau, (lei-many, have invented certain new and useful Improvements in the Manufacture of Glycoheptonic Acid, of whichthe following is a specification.

' Our present invention relates to the manufacture of glycoheptonic acid, the preparation of which by the process hitherto used is firstly expensive, owing to the fact that one must start from puredextro-glucose (grapesugar), and secondly occupies much time because the final product must be allowed to stand for some weeks in order that it may crystallize.

Now wehave found that, even when using commercial dextro-glucose, itris possibleto produce in a very simple way and with a good yield a pure andquickly crystallizing glycoheptonic acid, by treating with barium hydrate, cold orwith heat, the product obt-ained'by the addition of hydrocyanic acid to dextro-glucose, separating the precipitate which is formed after a short time and de-' our present process permits the direct use of potassium cyanid and acid.

As the product of the addition of hydro cyanic acid to dextro-glucose is transformed into the ammonium salt by the action of water, the operation may of course'also be carried out by decomposing the ammonium salt by means of a mineral acid, expelling the hydrocyanic ,acid from the liquid by heatin and then passing a current of air throug it and precipitating the glycohepmeans of barium hydrate, or barium carbonate and barium hydrate.

The following example illustrates our invention: 5 kilos of dextro-glucose and 25 liters of hydrocyanic acid of 3% strength, or preferably the corresponding mixture of potassium cyanid and hydrochloric acid, are heated for 6 days'at 25-30? C. For starting the reaction about 20 cc. of ammonia are added to the mixture. When the reaction is finished the hydrocyanic acid expelled, the mass is heated, and when the temperature has risen to C. there are added 8?; kg. of barium hydrate. At first the liquid remains clear, but after a short time precipitation occurs and finally a thick magma consisting of a finely crystallized precipitate is formed. After cooling, the mass is filtered, and the precipitate is thoroughly washed with Water and is decomposed in the usual manner by means of sulfuric acid The barium sulfate is filtered off and the filtrate is evaporated cacao and, if necessary, treated with animal charcoal, whereupon it can be easily crystallized.

Having now described our invention, what we claim is:

1. The process of manufacturing glycoheptonic acid, which consists in treating with barium hydrate the product obtained by the addition of hydrocyanic acid to dextro-glucose, decomposing the resulting precipitate with sulfuric acid, filtering off the barium sulfate, and causing the glycoheptonic acid to crystallize from the filtrate.

2. The process of manufacturing glycoheptonic acid, which consists in treating with bariumhydrate, cold, the product obtained by the addition. of hydrocyanic acid to dextro-glucose, decomposing the resulting precipitate with sulfuric acid, filtering off the barium sulfate, and causing the glycoheptonic' acid to crystallize from the filtrate-by evaporation.

3. The process of manufacturing glycohept-onic acid, which consists in treating with an acid the product of the addition of hydrocyanic acid to dextro-glucose, expelling the hydrocyanic acid from the liquid, adding barium hydrate, filtering the precipitate, washin and decomposing it with sulfuric acid ,-'fi tering ofi the barium sulfate, and evaporating thev filtrate, where-' heptonic acid, which consists in treating with an acid the product of the addition of hydrocyanic acid to dextro-glucose; expelldrocyanic acid from the liquid,

ing the by adding barium hydrate and carbonate, filtering the precipitate, washing and decomposing it with sulfuric acid, filtering ofi' the barium sulfate, and evaporating the filtrate, whereupon the glycoheptonio acid crystallizes out.

In testimony whereof, we aflix our signa- 15 turesin presence'of two witnesses.

Witnesses:

JEAN GRUND, @CARL GRUND. 

